Measuring instrument



A. P. JACOB MEASURING INSTRUMENT Filed Dec. 10, 1926 Feb. 26, 1929.

u w i 7 S} S\\\\\\\\\\\\\\\ A/fizd Jami ATTOR N EY Patented Fahd 26, 1929 I l r V UNITED STATES PATENT. oFFicE. v

Amman 2. Moon, or NEW Yonx. N. Y.

assume ms'rnun nnr. a ncmonmea December-10, 192a Serial no. 158,921.

This invention relates to'iinprovements in 11 having recesses or grooves 12 and 13 promeasuring instruments and has particular vided therein and which extend the length of reference to an instrument for finding the said body. The recess 12 is provided in the center of an. object or figure. v p face of the body while the recess 13 is dis.-

The primary object of the invention resides posed to one sideof and overlaps the same, .5 in anfinstrument which may be quickly adbut communicates therewith for a purpose to justed to the object to be measured, andwhen be explained. I i so adjusted, the same will visibly indicate the Rack bars 14 and 15 are slidablymounted exact center of the same without necessitatin the respective recesses 12and 13 and are ing the use of mathematics in sofinding the movable out of one of the ends of said body. same. '1 r 1 5 The outer end of the'rack bar 14 carries 'aws Another object of the invention is to pro- 16 and 16', these jaws being dispose revide a measuring instrument which. is autospectively on opposite sides of the longitudimatic and accurate in its findings and which nal axis of said rack bar with the noses. of

will not become easilydamaged through the jaws terminating in alignment with the 55 rough usage as it will be appreciated that longitudinal side edges of the body 11. The most measuring instruments are very dellrack bar 15 carries a single jaw 17 at the cate intheir construction and operat1on,- outer end thereof for co-action with the jaw A still further object of the invention re- 16 for a purpose to be presently explained.

sides in a combined center finder and cali- Disposed within the recess 18 provided in 1 pers, which may be used for respectively the body 11'. are pinions 19 and 20 for respecfinding the exact center of the object and tive engagementwith the'teeth of the rack also the exact thickness of the same. bars'let and 15. The pinions are of difi'erent A still further object of the invention is sizesand their ratio with respect to each other to provide a measuring instrument of the is two to one, the pinion'19 being twice the 75 type above mentioned which is simple in size of the pinion 20 so as to move the rack construction, easy of operationand inexpenbar 14 at twice the speed of the rack bar15. sive of manufacture. I v 1 j The pinions are keyed or fixedly mounted on With these and other objectsin view, the a shaft 21 which has its ends journalled in invention resides in certain novel-construc the body 11 and in a cover plate 22 which 80 tion, combination and arrangementof parts, covers one side of the body. Screws or like the essential features of whichare herein fastening elements 23 pass through the cover after fully described, are particularly-pointplate and into the body 11 for removably se-. ed out in the appended claims, and are illuscuring the cover plate thereon.

trated, in the accomp ny ng g, in The rack 14 is provided with graduations 1 which: 7 24 whichco-act with the end wall of the body Figure 1 is a perspective view of; my 1In-' when extended therefrom to indicate the disproved measuring instrument/ 1 tance between the inner face of the jaws 16 Figure 2 is an elevational view of the" same and the end of said body. The graduations 4 with the cover plate removed. 24 on the rack bar may be indicative of inches N Figure 3 is a vertical transverse sectional and'fractions thereof or any other scale used view on the line 33 of Figure 1 v for measuring thicknesses. Figure 4 is a Vertical transverse sectional In operation of the device, we shall preview on the line 4-4 of Figure 1. sume that it is desired to find thev center of an Figure 5 is a detail perspective View of object of any width,'the operator graspsthe thefpinion wheels. body of the instrument with one hand and Referring more particularly to the drawpulls out upon the rack 14-with his other hand ing. the reference numeral 10 designatesmy until thejaw 16 and the face 26 of the body improved measurin instrument in its en- 11 spans the object, at which time the gradua- 5 tirety and which inc udesan elongated body tion 24 on the rack bar which is indicative of the width of the object is in alignment with'the end of the body, this giving the exact width of the object. As the rack bar 14 moves outward, the pinion 19 is rotated which causes rotation of the pinion 20 which imparts a slow outward sliding movement to the rack'bar lfijcausing the same to move outward atone-half speed of the rack bar 14.

7 When the rack bar 14 stops moving, the outer ject being measured.

For finding the center of a circle with my instrument it is only necessary to adjust the 'aw 16 ,with respect to the face 26 as hereln- Y before described so that the same touchthe circleat diametrically opposite points after which a mark is placed within the circle at the point where the jaw 17 stops. The 1n strument is then shifted aboutthe circle and anothermark placed within the same to cross the first mark. The point of intersection of the two marks represent the exact center of the circle.

I When the racks 14 and 15 are at thelimit of i as calipersj'the jaw 16' their inward movement, the jaw 17 is disposed in a recess 27 so that the outer face of the jaw lies flush with theedge of the body to permit the jaws 16 and 16 to abut the end of the body. I a Should it be desiredto use the instrument co-acts with the face 28 of the body for spanning the thickness of the object 'beingmeasured, which thickness is 7 indicated by the e oaction of the indicating marks 24 with the end of the bodyl'l.

The instrument may be constructed of any suitable light material so as to' permit the same to be conveniently carried in the pocket ofa user. In constructiong the same the body 11 may of bass-wood or the'like while the cover plate 22 may be of metal. The racks 14 and 15 should always be of metal with the scale impressed in the rack 14;

- From the foregoing description, it will be i seen that I have provided a, measuring instrument which may bequickly adjusted to the size of anobject, and when adjusted the exact center of the object is found. The instrument finds-the center without requiring the knowledge of mathematics and'may be used by persons not well versed therein.-

WVhilel have described what I deem to be the most desirable embodiment of my inven tion, itis obvious thatmanyof the details may be varied without in any way departing from the'spirit' of my invention, and I therefore do not limit myself to the exact details ofv construction herein set forth nor to any:

thing less than the whole of my invention limited only by the appended claims.

What'is claimed as new is 2'- 1. A measuring instrument comprising a body, a pair of rack bars slidably mounted within said body and movable through one end thereof, a jaw carried by the outer end of each rack bar, a pair of pinions of different ratios journalled within said body on the same axis and movable together for co-action with the respective rack bars, substantially as and for the purpose specified.

2. A measuring instrument comprising a body having longitudinal recesses therein, rack bars s1idably mounted in the respective recesses, a jaw on each of said rack bars, a pair of'pinio'ns of different ratios journalled within said body on the same axis and movable together "force-action with' the respective rack bars for moving the same at different rates of'speed, a scale provided on one of said rack bars for co-ac tion with one end of said body for indicating the distance of movement of said rack bars out of said body.

7 3. 'A measuring instrument comprising a body having longitudinal recesses therein, rack bars slidably mounted in the respective recesses, a single jaw on one of said rack bars, a double jaw on theother of said rack bars, a pair of pinions of'different ratios journalled within said body on the same axis and movable together for co-action with the respective rack bars for moving the same at different rates of speed, and a scale provided on the last mentioned rack bar for co-actionwith said single jaw for indicating. the distance of movement of said rack bar out of said body.

4. A measuring instrument; comprising a body,. a pair of rack bars slidably mounted therein and movable through'one end thereof,a single jaw fixed to the outer end of one of said rack bars and movable into a recess in said bodywhen' in a fully retracted position, a double jaw fixedto the outer end of the other of said .rack bars and adapted to' fit against the body when in afully retracted position, a pair of pinions of different ratios journalled within. said body and constantly meshing with said. rack bars, the pinion meshing with the rack bar carrying, the single jaw being one-half the gear ratio of the other pin ion meshing with the rack bar carrying the double jaw, whereby the single jaw rack bar moves'at half the rate of speed to that of the double jaw rack bar during extension and re; traction of the. same. a

5. A measuring instrument comprising a body, a pair of rack barsslid'ably mounted therein and movable through one end thereof, a single jaw fixed totheouter end'of one of said rack bars and movable into a recess in ion meshing with the rack bar earryin the double jaw, whereby the single aw rac bar I moves at half the rate of speed to that of the with one end of said body to indicate the disv tance between the end of said body and said double jaw, and for co-action with said single jawfor indicating one-half the distance 1 therebetween.

In testimon ture.

y' whereof I aflix my signa- ALFRED JACOB. 

